(1) Field of the Invention
The present invention relates to a jointing sleeve component used for electrically connecting a plurality of core wire ends to each other, at each of which core wire end an insulating coating of a coated electric wire is removed, and a joint electric wire.
(2) Description of the Related Art
So far, when a joint electric wire has been formed, a pipe-shaped sleeve, both ends of which are formed open, has been used. As shown in FIGS. 7A and 7B, a long pipe material is cut into a specific length thereof and thereafter, subjected to plating, thereby the sleeve 41 is obtained.
When core wire ends 43b are connected to each other by using the sleeve 41, the core wire ends 43b are inserted from one end 42a of the sleeve 41, then front ends of the core wire ends 43b are exposed from an opposite end 42b of the sleeve 41, then the sleeve 41 is subjected to provisional crimping by using a crimping tool such as a hand tool, then the sleeve 41 is inserted in between dies 45 facing each other of rotary swaging device and then, the sleeve 41 is uniformly reduced in its diameter by swaging, so that the sleeve 41 and the core wire ends 43b are closely crimped to each other without a gap.
As another conventional example of the sleeve, proposed is a sleeve for a shielded electric wire, which is mounted to an end of one shielded electric wire and by which an inversion processing of a braided wire can be easily effectively performed (Japanese Patent Application Laid-Open No. 2002-216916) or a sleeve, which is mounted to an end of one coated electric wire for connecting an electric wire and a terminal to each other (Japanese Patent Application Laid-Open No. 2001-326053).
However, since a long pipe material is manufactured from a board material by consuming a lot of time and labor hour through many steps such as pressing, rolling and welding, therefore there is a problem that a material cost is high. Further, since it is not easy to subject additional processing such as spreading and pressing to a pipe material, therefore there is a problem that a production cost is high. Accordingly, so far, a pipe piece, which is obtained by cutting a pipe material, has not been subjected to any processing or, alternatively, an additional processing is limited to a processing, in which a guiding taper is formed at an open end of a sleeve.
Moreover, since dimensions of inner and outer diameters are determined to some extent, therefore there is a problem that it is not possible to obtain a pipe material having a dimension in accordance with a size of an electric wire. Accordingly, when the number of coated electric wires 43 to be jointed is changed or when a thickness of a coated electric wires 43 is changed, a size of the sleeve 41 cannot be changed according to a size of the electric wire 43 causing a fluctuation in a gap between the sleeve 41 and the electric wires 43, causing a problem that the electric wires 43 are excessively compressed or insufficiently compressed and a crimping force fluctuates depending on the size of the electric wire 43, and a uniform crimping force cannot be attained.
In order to prevent the sleeve 41 from moving along the coated electric wire 43 during swaging, the sleeve 41 is crushed by using a crimping tool or the like so as to be provisionally crimped to the core wire ends 43b. However, when the sleeve 41 is crushed into a deformed shape, the property of the swaging is deteriorated, causing a problem that the sleeve 41 and the core wire ends 43b cannot be provisionally crimped to each other sufficiently firmly. If the provisional crimping force is weak, the sleeve 41 might move during swaging, causing a problem that the insulating coating 43a is caught by the sleeve 41 moved causing breakage of the insulating coating 43b or deterioration in crimping force of a swaged part.
Moreover, when the sleeve 41 and the core wire ends 43b are provisionally crimped to each other, a jig for positioning or the like must be used in order to fix a positional relation between the sleeve 41 and the core wire ends 43b, causing a problem that workability in connection of a joint electric wire is deteriorated.